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By Frederick N. Rhines

BECAUSE of the nature of the environments in which metals are handled, it is natural that gases should be suspected of intruding into metallurgical operations, there to produce effects both beneficial and detrimental. The problem of tracing and controlling such effects is often made difficult by the complexity of the conditions surrounding 'their occurrence, even though the fundamental mechanisms involved may be simple and of familiar type. Many gas-metal reactions are known to be implemented by processes of diffusion. These form a homogeneous group of phenomena which become more readily understandable when viewed together, in that the knowledge gained from one serves to interpret the next. It is the purpose of the present paper to present, by means of examples drawn from practice, a brief survey, of the ways in which gas-metal diffusion serves and obstructs the purposes of the metal-fabricating industries. The selection of the cases described was made by consulting more than thirty-six practicing experts whose combined experience provided an extensive coverage of the field and who were in a position to supply examples of occurrences of present day interest. The response was generous and it is regrettable that space permits the description of only a limited number of typical examples with but brief mention of parallel cases. THE NATURE OF GAS-METAL DIFFUSION The term "gas-metal diffusion," although commonly used, is ambiguous in so far as it implies that a definite group of substances may be identified as gases and may be expected to behave in a manner distinct from other substances in association with metals. "Gases" such as oxygen and hydrogen when diffusing through a liquid or solid metal are properly components of the liquid or solid solution; they behave as alloying elements and are not to be distinguished in their diffusion characteristics from other elements, except that each has an individual rate of diffusion. On the other hand, a number of metals in certain temperature ranges are volatile to the extent that they may appear in the form of vapor in metallurgical operations. For the sake of greater definiteness, therefore, it will be convenient to- regard as "gas-metal diffusion" any process in which the result depends upon one or more of the diffusing elements appearing, at some stage, in the gaseous state, or as a compound gas. No element, gaseous or otherwise, can diffuse through a liquid or solid metal unless it is at least slightly soluble in that metal. The elements of low atomic number

Jan 1, 1944

Arthur Jarman, Sydney, New South Wales, Australia (communication to the Secretary*):—All designs for modern metallurgical and chemical laboratories should provide each student's desk with a hood or cupboard for the removal of fumes, but I doubt the advisability of placing air-baths and similar apparatus close to the hot plate. It seems to me that unless the draft be exceptionally strong the fumes from ordinary wet assay work will corrode the iron-work of the fittings, in which case the baths would have to be removed to a general desk in order to lighten the work of the laboratory attendant. Since the laboratory described by Mr. White has been in use for two years, I should like to ask if any inconvenience has resulted from this corrosion. If not, it is certainly an important improvement to have the air-baths and similar apparatus placed on the student's desk. The hoods described by Mr. White are supplied with a good draft by means of a fan, which gives them a great advantage

Jan 1, 1905

By K. R. Evans

The deformation mechanisms occurring in polycrys-talline, commercially pure titanium and a Ti-8 pct A1 alloy have been investigated and compared to earlier results by Levine on high-purity titanium single crystals and by Conrad on commercially pure titanium. In accord with Levine, two consecutive deformation mechanisms are observed to exist below 500°K with the transition temperature between mechanisms, Tc, strongly dependent upon interstitial composition. T, is found to be 210°. 375° -430°, and 450°K for alloys A large number of investigations have been conducted to determine the rate-controlling mechanisms of plastic deformation occurring in fcc and bcc metals. Very few investigations of a similar nature have been conducted for hexagonal metals. In fact, until very recently, magnesium is the only hexagonal metal which has been systematically investigated for determination of the rate-controlling deformation mechanisms.1"3 From these investigations, it was concluded that basal slip below 420°K occurs by the intersection of forest dislocations,1'3 while for prismatic slip the Peierls mechanism is rate-controlling at low temperatures with interstitial compositions of 0.024, 0.42, 0.61, and 1.13 at. pct expressed in terns of oxygen equivalents. The low-temperature mechanism is found to be an impurity obstacle mechanism in contrast to Levine's earlier conclusion of the Peierls barrier. Measurement of the activation parameters for deformation and estimation of the force-distance profile of the obstacles show their retarding force to be effective over longer distances from the obstacle as the interstitial composition increases. and thermally activated cross slip at higher temperatures. 2 The potential technological importance of titanium alloys has prompted recent studies of the deformation and fracture characteristics of titanium and its alloys. 4-8 Levine' systematically investigated the low-temperature deformation behavior of high purity titanium single crystals oriented for either basal or prismatic slip. It was concluded that the Peierls mechanism was rate-controlling at temperatures below 210°K, while above this temperature an undefined mechanism was rate-controlling. Conrad 7,8 concluded from an analysis of the composition dependence of the critical shear stress at 0°K and measurement of the activation parameters that the low-temperature deformation of titanium is controlled by an impurity

Jan 1, 1969

Institute of Metals - Iron and Steel - Mineral Industry - Industrial Minerals Year ?Division - Petroleum Division ? Division - Coal Division - Education Division -Division 1918 W M CORSE 1919 1920 W. H BASSETT 1921 1922 W B PRICE RALPH ARNOLD 1923 E DEGOLYER 1924 G K ELLIOTT 1925 F JULIUS FOHS 1926 PAUL D MERICA 1927 JOHN M LOvEJOY 1928 S SKOWRONSKI A W AMBROSE RALPH H SWEETSER

Jan 1, 1952

By C. S. Duncan, S. Scuro, D. R. Muss

Work is vepurted which was aimed at accentuating the pec14liar attributes of the GaAs laser diode, namely its sutzull size and its high efficiency. This has been done by reducing- transport losses in the bulk p and n regions of the diode and combining many of. these diodes into series stacks with common optical cazlities. The result of this effort is a nearly monochromati source at about 8450A With a luminous areu 0.05 by The GaAs laser diode is an attractive pulsed light source in the near ir because of its ability to emit very large pulse powers and its small size. In addition to this, the device is efficient; and the higher the 0.05 cm emitting peak pulse po we rs at greater than 300 LC at repetition rates below 200 pps into a cone about 0.01 steradians when operated at 77°K. The results of nzeasuvetnents of peak optical power and spectra frorr~ these stacks are reported and some conclusions are drawn about the vole the individual diodes play in the stacked operation. peak output power, the more efficient it is. The limit for the amount of power that these diodes can emit is the transient and average dissipation associated with the pumping pulse. This power dissipation arises primarily from transport across the bulk regions of the diode; this fact, along with the relatively low thermal conductivity of the GaAs, led us to the conclusion that higher power

Jan 1, 1968

By Harrison Souder

MAGNETITE mining and milling in the Eastern States showed continuing improvement during the year. Some of the smaller mines remained idle, but the larger operations responded promptly to the improved situation in the iron and steel industry. The output of ore for 1936 was over twice that for 1935. A number of improvements were made in mine plant and equipment, and operating forces were increased and maintained at near normal. The coming year should see additional mines started up and production increased at the larger properties.

Jan 1, 1937

By Oliver C., Ralston

THE following data were obtained during Tan exhaustive research into the possibilities of concentrating United Verde massive sulfide copper-zinc-iron ores by flotation. The composition of these ores approximates the following mineralogical analysis: 3 to 15 per cent chalcopyrite; 3 to 11 per cent marmatite (ferruginous sphalerite) ; 47 to 69 per cent pyrite; and 10 per cent quartz. The remainder is usually schist gangue. The sulfide minerals are finely dis-seminated; chalcopvrite and marmatite begin to be liberated on grinding at about 100 mesh, but complete liberation from gangue (pyrite in this case is considered a gangue mineral) is

Jan 1, 1935

By S. K. Nicol, A. R. Swanson, J. C. Day

Addition of oil to a suspension of hydrophobic coal particles can influence its dewatering characteristics. An agglomeration process occurs in which coal particles are held together by negative capillary pressure at particle/oil/water contacts. Consequently, the units round which flow can occur are enlarged and this improves dewatering parameters such as drainage rate, solids recovery, and equilibrium moisture content. This paper discusses processes which attempt to use this principle, in terms of metallurgical and economic efficiency. The discussion is augmented by results of recent experiments on the effect of oil addition to centrifuges and vacuum filters.

Jan 1, 1980

By T. T. Read

FOR the second time the Mineral Industry Education Division opened the sessions at the Annual Meeting by gathering at the Engineering Woman's Club, Sunday at 3 p. in., and, in spite of the informality of the hour, with a good attendance of representative men in the educational field. The chairman of the Division, Thomas T. Read, after briefly reviewing some of the more significant events of the past year, introduced H. P. Hammond, professor of civil engineering, Brooklyn Polytechnic Institute, a leading figure in the project of the Engineers' Council for Professional Development for accrediting engineering schools. Prof. Hammond made it clear that the project is not to rate engineering schools but to accredit them; not to arrange them in order of excellence, but to segregate them into two groups, those that are entitled to recognition as genuine engineering schools, and those that are not. About thirty schools in the whole country will presumably fall into the latter class; they are typified by an unnamed institution where the teacher of mathematics bears the title of Professor of Civil Engineering and the man who teaches chemistry that of Professor of Chemical Engineering, and having no engineering instruction except some elementary surveying, but still claiming in its catalogue to be an engineering college. While everyone would like to avoid the necessity of accrediting engineering colleges, it cannot be avoided, since the University of the State of New York, and several other agencies, are already doing it. If it cannot be avoided it is best that it should be done by a qualified agency set up by the national engineering societies, so that the results may command respect and general acceptance. It is for this reason, and this alone, that the accrediting committee of the E. C. P. D. has been set up. It is now ready to begin its task, and during-the coming year it will accredit the schools in two of the seven geographical districts into which the country has been divided, beginning with New England and the Mid-Atlantic States.

Jan 1, 1935

By D. L. Passmore, J. D. Bennett

The degree of injury and days lost from work due to an injury are examined for selected electrical sources, occurring in conjunction with falls of the injured miner or with selected machinery, that could have been eliminated by use of diesel equipment. Although the number of preventable electrical source injuries is small relative to the total number of injuries during the period examined, many lost-time injuries could have been precluded and thousands of days lost from work could have been avoided.

Jan 1, 1986

By H. B. FERNALD

THE first year to which the Revenue Act of 1936 has applied is now passed. It is appropriate to try to give some calm thought to the plan of Federal income taxation as now imposed and what it will mean to the business and industry of the country if this plan of taxation is continued unchanged. Whether or not we like to pay these taxes is beside the point. Taxes are high and may be expected to be high for many years. The important question is whether the taxes to be imposed will destroy or injure business enterprise and development, and, in so doing, lower the standards of employment, living, comfort, and welfare of our people. The power to tax is the power to destroy. That destruction may come suddenly as a cyclone, or slowly as dry rot. What, if any, features are there in the present plan of Federal income taxation that have these destructive tendencies? A few of the points follow that seem to call for consideration.

Jan 1, 1937

By James T. B. Ives

The map exhibited* as an example of my method of construct ing geological strata-maps is essentially an educational appliance. The method, however, is available for the production of maps of comparatively small areas, which, I am confident, will be found of great practical value to mining engineers. Before stating how the method may be so applied I will briefly describe the map exhibited, as the easiest way of making my meaning clear. Almost any region might be taken. This map represents the eastern half of the United States; and the geology is that of the map issued by the Geological Survey, and revised and extended subsequently by Professor Hitchcock for your Institute. I use ten cards, of the colors used in the geological map, each having the geog raphy of the area printed upon it; and I superimpose these in the order in which the colors occur in the index to the map. I next cut away a portion of each card, excepting the lowest, leaving only so much of each as represents the exposure of the formation of that color plus all those which overlie it. When that is done, the whole, looked at from a distance, appears to be an ordinary geological map. Looked at more closely, however, the formations are seen to overlie one another, as in nature. The cards are covered with glass in a frame, which, hinged at the bottom edge, can be let down. The cards are then found to be all hinged in the same manner, and they, too, may be lowered, one after the-other. I am told by teachers of geology of great experience and the highest reputation that by this appliance they will be assisted in im parting to students the first facts and principles of geological sci ence. Having let down the whole series of cards, until that repre senting the Archaean is seen underlying all the rest, the teacher will gradually rebuild it. The Cambrian will thus be laid down upon the Archaean before the eyes of the class, the Silurian upon that,

Jan 1, 1888

By John J. Collins

The plight of the Japanese mining business is pitiful. Coal mines were given the highest priority for all materials they needed, yet between the end of the war and June 1948, the government was obliged to subsidize them to the extent of 22 billion yen, this being the difference between the consumer's price and the producer's price. Most of the metal mining companies have been operating at only one fifth to one third of war-time production rates, and financial losses have been terrific. The chief difficulties have been a plethora of office workers and a dearth of equipment, supplies, and miners. The principal material needs at metal mines are steel rails. cars, plates, nails, rubber hoses, and belting, to say nothing of modern core drills which are totally lacking. Until recently the great shortage was in coal; for lack of fuel the smelters and factories failed to produce the very metals and equipment now needed to operate the mines. Nation-wide shortages have created a monstrous inflation of prices throughout all the economy, currently amounting to 200 times the prewar figures. For example, the price of copper ranged from 500 to 900 yen per metric ton for many years until 1937, but in mid-1948 producers were

Jan 1, 1949

By Emile Rector Abadie

The picturesque little mining town of Grass Valley, nestled in the foothills of the Sierra Nevada mountains, at an altitude of 2500 feet, has been for 43 years the scene of uninterrupted activity and prosperity, as the center of a mining district which was intimately associated with the pioneer days of California, and the discovery of gold by James W. Marshall, in El Dorado county, in January, 1848. Although placer-mining was inaugurated in Nevada county as early as 1848, the first quartz ledge was not located until the summer of 1850. Discoveries made on Gold Hill and Massachusetts Hill increased the excitement in quartz-mining, and hastened the erection (during the same year) of the first mill operated in the State. At the close of 1864, the district had produced $23,000,000 in gold, and all the well-known properties of to-day had been discovered and worked. The Eureka-Idaho, the North Star, and the Empire mines were in active operation ; and to-day we still find them equipped with large crushing-plants, operating 80 per cent. of all the stamps in the immediate Grass Valley district. Of the mines just named, the North Star possesses the most recently constructed mill, a description of which, the writer believes, may prove of interest to members of the Institute engaged in the milling of goldores. During the year 1386, operations at the North Star mine (the property of the North Star Mining Company) had reached such a stage of development that the necessity of a crushing-plant at the mine became imperative, and early in October the erection of a 30stamp mill was in progress. The building designed to contain 40 stamps was speedily erected ; and within sixty days the large structure was under cover. Plate A represents the appearance of the mill 40 days after work was commenced. Late in February, 1887, the mill was in readiness, and, upon the

Jan 1, 1895

By C. M. EYE

IN the spring of 1905 I was employed by Messrs. Bradley and Requa, under our fellow member, Thomas Cox, on the mill plans for the Nevada Consolidated, when an opportunity came to go to the Philippines to erect a small mill on the property of the Benguet Consolidated. This I accepted, expecting to be away eight months or so, but it was seven years before I got back. .I sailed in May, on the Coptic, having as room-mate as far as Kobe, A. E. Drucker, who was going out to Korea for the Oriental Consolidated. It was the first trans-ocean trip for either of us, and we had some rather unusual experiences. This was toward the close of the Russo-Japanese war and the Russian fleet was known to be on the way from Suez to Asiatic waters, but it was a matter of doubt whether they would risk a passage between Japan and the mainland, or take the longer but obviously safer route outside of Japan. The Coptic carried much contraband of war for Japan, so naturally did not care to meet this fleet. No definite word being available at Honolulu, we went to the Midway Islands, but the cable station there had very little information to offer, so we proceeded cautiously toward Japan. On the last afternoon out, we steamed due north at half speed for several hours, and finally sneaked into Yokohama at night, to learn that ' the Russian fleet had met the Japanese the day before and had been annihilated. We sailed over the spot in the Sea of Japan a week later, and when we got to Manila we found three of the Russian boats interned and being guarded by the monitor Monadnock and a cruiser. This was only a matter of form, as the Russians were only too glad to be there for the rest of the war, and the boats could not have gone far anyway, for they were literally shot to pieces. The Admiral's flagship had a hole within 3 ft. of the water line, for ward, through which a man could enter by stooping.

Jan 1, 1929

By J. D. MacKenzie

THE world production of copper for the first eight months of 1927 shows an increase of 3 per cent over the same period in 1926. Since February of this year, however, production has been considerably curtailed. The United States reduction in the last four months has been offset by the increased South Ameri-can and Belgian Congo production. The United States is now producing 58 per cent of the world production, Chile and Peru 17.3 per cent, Belgian Congo 5 per cent. In 1926 the United States produced 54 per cent, Chile and Peru 16.3 per cent, Belgian Congo 6.3 per cent. Production, Tons 1917-largest war year 1,580,000 1925 1,581,000 1926-increase 3 per cent 1,628,000 1927-increase 3 per cent 1,670,000 Copper Producing Countries, 8 mo., 1927: Tons Per Cent United States 644,000 58.0 Chile and Peru 192,000 17.3 Europe 90,000 8.1 Belgian Congo 56,000 5.0 Japan 46,000 4.1 Mexico 30,000 2.7 Canada 23,000 2.1 Figures are not available for Spain and Portugal, which would probably precede Mexico.

Jan 12, 1927

By AIME AIME

A REGULAR meeting of the Executive Board 'of American Engineering Council was held in the Onondaga Hotel, Syracuse, N.. Y., Feb. 14, 1921, with the president, Herbert Hoover, presiding. Reports of committees were presented and acted upon as follows: ENGINEER ON INTERSTATE COMMERCE COMMISSION The second meeting of the Committee was. called because it was represented to the Committee' on Pro¬cedure that the American Society of Civil Engineers, the American Association of Engineers, and the Ameri¬can Institute of Consulting Engineers were anxious to have President-elect Harding appoint an engineer to fill one of the vacancies on the Interstate Commerce Commission. The representative of The American Society of Civil Engineers agreed to endorse the recom¬mendations- of American Engineering Council, and the Committee on Procedure prepared and sent a letter to the President-elect, a - copy of this letter being sent to each member of the Board. No names were suggested. . The appointment of an engineer on the Interstate Commerce Commission was approved and the Board, after approving the action of the Committee 'on Procedure in writing the President-elect, voted that, if requested, the Committee on Procedure submit a list of not less than six names for the appointment of an engineer on the Interstate. Commerce Commission.

Jan 1, 1921

By Schlumberger, C

IN the search for practical geological problems amenable to solution by the potential methods, the geophysicist is led to study mathematically various theoretical cases. In these idealistic discussions, the media under consideration are generally supposed to be homogeneous and iso-tropic. The geophysicist, of course, realizes perfectly that these condi-tions do not occur in their entirety in reality. However, the assumptions made are justified, because very often they are necessary in order to render possible an exhaustive study of a given problem, which otherwise would be too complicated, and would not lend itself to a complete mathe-matical analysis. Of the above two assumptions, that concerning the homogeneity of a given geological formation is satisfactorily realized except in so far as isotropy is concerned, since this property is not often encountered in practice. As a consequence, it is very desirable for the geophysicist to have quite an extensive knowledge of the properties of anisotropic forma-tions, and of the laws that govern the propagation of electric current therein. With such principles in mind, he will be able to decide whether the conclusions arrived at in simple, isotropic conditions are still correct in more complex cases, or in what way they must be modified or adapted in order to constitute a sound basis for the interpretation of the results obtained in anisotropic media. On the other hand, the fact that in anisotropic formations themobility of the ions is greater along the strike than perpendicular thereto can be utilized for determining the direction of the dip by induc-tion measurements. We therefore propose to study in three successive chapters the following points: 1. Propagation of the electric current in anisotropic media. 2. Some consequences of the anisotropy of geological formations with reference to the surface electrical measurements, and their interpretation. 3. Determination of the direction of the dip of anisotropic formations by surface induction measurements.

Jan 1, 1933

By E. S. Grumell

The correct sampling of coal and coke is becoming important to an ever increasing number of producers and consumers. This, therefore, may be an opportune moment to examine where we stand with regard to existing and proposed methods. In this paper an attempt will be made to review, as briefly as possible, some of the considerable amount of painstaking research which has been done in the last 10 years, and which has unquestionably led to a much better understanding of the subject. In so doing we shall try, on the one hand, to make clear where substantial progress has been made, and on the other hand, to draw attention to points that require further investigation. The paper is divided into sections in order to emphasize the major divisions of the subject; further, in order to retain this emphasis, detailed consideration of some of the points has been relegated to appendixes. No attempt has been made to give a complete survey of the literature, as this has already been done by L. A. Bushell.2 The following abbreviations will be used: A.E., average error; P.E., probable error; S.W.R., size-weight ratio; B.S.I., British Standards Institution. Section 1.—Cost It has often been stated that the cost of sampling should bear some relationship to the value of the product, and since coal is a relatively cheap raw material it would be a major error to specify, for ordinary commercial purposes, elaborate and costly methods of sampling which nobody would adopt. Specifications must be of such a nature that they will be used. We believe that one of the achievements of the last 10 years has been to reduce the cost of sampling. There is, however, another point to be considered; via., that the cost of sampling should bear some relationship to the value of the investigation. Correct sampling is a cog (possibly a small one) in the wheel

Jan 1, 1940

By E. S. Grumell

The correct sampling of coal and coke is becoming important to an ever increasing number of producers and consumers. This, therefore, may be an opportune moment to examine where we stand with regard to existing and proposed methods. In this paper an attempt will be made to review, as briefly as possible, some of the considerable amount of painstaking research which has been done in the last 10 years, and which has unquestionably led to a much better understanding of the subject. In so doing we shall try, on the one hand, to make clear where substantial progress has been made, and on the other hand, to draw attention to points that require further investigation. The paper is divided into sections in order to emphasize the major divisions of the subject; further, in order to retain this emphasis, detailed consideration of some of the points has been relegated to appendixes. No attempt has been made to give a complete survey of the literature, as this has already been done by L. A. Bushell.2 The following abbreviations will be used: A.E., average error; P.E., probable error; S.W.R., size-weight ratio; B.S.I., British Standards Institution. Section 1.—Cost It has often been stated that the cost of sampling should bear some relationship to the value of the product, and since coal is a relatively cheap raw material it would be a major error to specify, for ordinary commercial purposes, elaborate and costly methods of sampling which nobody would adopt. Specifications must be of such a nature that they will be used. We believe that one of the achievements of the last 10 years has been to reduce the cost of sampling. There is, however, another point to be considered; via., that the cost of sampling should bear some relationship to the value of the investigation. Correct sampling is a cog (possibly a small one) in the wheel

Jan 1, 1940